Electrooptical displays with polymer localized in vicinities of substrate spacers

ABSTRACT

There is a liquid crystal display device with two substrates facing and spaced from each other, at least one of the substrates being transparent. Electrodes are positioned to establish an electric field in the space between the two substrates. One or more space elements are located between the substrates. One or more polymer supports are located primarily in the vicinities of the spacer elements. The polymer supports extend between the two substrates and have been polymerized in situ in response to polymerization initiating or enhancing (PIE) material carried on or within the spacer elements. Electrooptic material (e.g., liquid crystal) fills at least a portion of the space between the two substrates.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority from U.S. ProvisionalApplication Serial No. 60/268,176, filed on Feb. 12, 2001.

BACKGROUND OF THE INVENTION

[0002] This invention relates to liquid crystal and other electronicdisplays.

[0003] Commercially, it is highly desirable for an electronic display tobe as thin and light as possible while still maintaining a high degreeof ruggedness and imperviousness to forces that are a consequence ofshock and drop. In the area of mobile electronics, such as cell phonesand personal digital assistants (PDAs), size and weight are criticalfactors to the commercial success of a product, but currently breakageof the displays within these devices remains the primary cause ofrepairs and product returns. In addition, the need for electronicdisplays that can actually be bent has been acknowledged in severalareas: so-called ‘electronic paper’ in which fiber paper is replacedwith a display would be much more compelling as a product if theelectronic display could be rolled up or folded like traditional paper;wearable electronics such as computers or multifunction watches would bemuch more comfortable to the wearer if the display were to conform tothe user's body; chip cards which have strict flexure life-testperformance standards would be able to incorporate flexible displays andstill conform to those standards. Replacement of the glass substrateswithin displays with plastic film has been an area of active researchwithin the display community for a number of years.

[0004] Electrophoretic displays achieve images via electrophoretics—therapid migration of microparticles in colloidal suspensions. Lightscattering particles are moved within a dyed colloidal suspension byelectrostatic forces. The particles will either move toward the viewer,in which case, the typically white particles are seen by the viewer, orto the surface away from the viewer, in which case, the white particleswill be hidden by the dark dye.

[0005] Cholesteric displays are another display technology beingattempted on plastic substrates. When sandwiched between conductingelectrodes, cholesteric liquid-crystal material can be switched betweentwo stable states—the so-called focal conic and planar states—in whichthe liquid crystal's helical structures have different orientations. Inthe focal conic state, the helical structures are unaligned and theliquid crystal is transparent. In the planar state, the helicalstructures' axes are all perpendicular to the display's surfaceresulting in essentially monochromatic transmission by the display.

[0006] The Gyricon display being developed by Xerox, is made ofmicroscopic beads, randomly dispersed and held in place between twoplastic sheets by a flexible elastomeric matrix of oil-filled cavities.The balls have strongly contrasting hemispheres, black on one side andwhite on the other. The white side is highly reflective, while the blackside absorbs light. Each hemisphere has a unique intrinsic charge,resulting in a force on the ball when an electric field is applied andthe axis of the ball isn't aligned with the field. The side of the ballpresented for display depends on the polarity of the voltage applied tothe electrode. In all three of these cases, while they have somepositive features such as high contrast and compatibility with plasticsubstrates, they all currently high drive voltages, have slow responsetimes, and are not compatible with commercially available driveelectronics.

[0007] Liquid crystal displays (LCDs) are attractive because of the lowdrive voltages required to switch them, their relatively fast responsetimes, the wide availability of drive electronics, and the significantintellectual and manufacturing investment in the technology. Attemptshave been made to develop LCDs that intermixed the liquid crystal withina polymer matrix in order to make them compatible with plasticsubstrates, one example being polymer dispersed displays (PDLCDs).PDLCDs are fabricated by intermixing the liquid crystal and apre-polymer into a solution prior to assembling the display. Afterassembling the display, the polymer is cured, typically by ultravioletlight. During the polymerization the LC separates out from the polymerinto microscopic droplets. Since the droplets of LC are not in contactwith any alignment layer, the orientation of the molecules is random andlight is scattered by the droplets. Applying a voltage to the electrodesof the PDLCD causes the LC molecules to become aligned, resulting in thedisplay becoming transparent. Like the other flexible displays, PDLCDsrequired high drive voltages not generally compatible with existingdrive electronics. Prior art such as U.S. Pat. Nos. 4,688,900,5,321,533, 5,327,271, 5,434,685, 5,504,600, 5,530,566, 5,583,672,5,949,508, 5,333,074, and 5,473,450 all make use of phase separation ofan LC/polymer mixture during polymerization of the polymer using lightas the curing mechanism (photopolymerization).

[0008] Methods have been developed to achieve anisotropically dispersedLC/polymer structures which might have drive voltages lower then thoseachieved in PDLCDs. U.S. Pat. No. 5,949,508 describes a method in whicha lamellar structure is achieved whereby the LC and polymer are disposedon opposite substrates; this reduces the drive voltages necessary toswitch the device, but results in a structure where it is only practicalto have the rubbed alignment surface on one of the substrates. Whilethis structure is effective with nematic or electrically controlledbirefringence (ECB) displays, it becomes more difficult to constructdisplays such as twisted nematic (TN) and super twisted nematic (STN)which typically require alignment surfaces on both substrates. U.S. Pat.Nos. 5,473,450 and 5,333,074 describe methods of localizing the polymerduring photopolymerization by exposing only portions of the device tothe light source using masks. Polymer structures of a size on the orderof a pixel (˜0.3 mm) are achievable, but manufacturing may be moredifficult since the photomask must generally be aligned to the electrodestructure within the device and expensive collimated UV light sourcesmust generally be employed. Structures much smaller than 0.3 mm may bedifficult to achieve due to the inherent scattering of the LC/polymermixture. U.S. Pat. No. 5,473,450 teaches the patterning ofphotoinitiator onto the alignment layer, but this method generallyrequires a highly accurate, screened deposition of the chemicalphotoinitiator onto the substrates. Proper alignment of thesilk-screening mask to the clear ITO electrodes may be difficult toachieve, and the introduction of chemicals directly onto the polyimidealignment surface may result in poor alignment of the LC to thealignment surface, poor appearance of the display and lowermanufacturing yields.

[0009] In addition to the breakage problems due to shock and drop, glasssubstrate displays also have difficulty surviving extremes oftemperature. When the temperature of a display is cycled between coldand hot it will sometimes develop small voids between the spacers andthe liquid crystal fluid. While the voids are small in size, theytypically are noticeable enough that the display will be returned forrepair. The voids are due to the mismatch in the thermal coefficients ofexpansion between the LC and the typically glass or plastic spacers.When a glass substrate display is assembled at room temperature and thensealed, its volume is essentially fixed at that point. As the display iscooled down, both the LC and spacer material will contract but due tothe mismatch in the thermal coefficients of expansion and the mechanicaldiscontinuity at the spacers, stress is localized around the spacers andvoids develop. Initially, the voids are small areas of vacuum or verylow pressure, but the more volatile components of the LC quickly move toa gaseous phase to fill the void to achieve a lower energy equilibriumstate. When the display is returned to room temperature, the vaporfilling the voids prevents the voids from being absorbed back into theLC, and the damage is typically permanent. Display manufactures havesolved this problem by, amongst other methods, utilizing speciallyfabricated spacers that have a softer, more compliant exterior coatingsurrounding a core of either glass or plastic. The outer compliant layeracts to relieve the stresses encountered during thermal cycling of thedisplay, thus preventing the voids. Because of the difficulty ofmanufacturing these spacers, they are often 10-20 times more expensivethan regular spacers and so are often used only when absolutelynecessary.

SUMMARY OF THE INVENTION

[0010] In general, the invention features a liquid crystal displaydevice comprising two substrates facing and spaced from each other, atleast one of the substrates being transparent, electrodes positioned toestablish an electric field in the space between the two substrates, oneor more space elements located between the substrates, polymer supportslocated primarily in the vicinities of the spacer elements, the polymersupports extending between the two substrates and having beenpolymerized in situ in response to polymerization initiating orenhancing (PIE) material carried on or within the spacer elements, andelectrooptic material filling at least a portion of the space betweenthe two substrates.

[0011] In preferred implementations, one or more of the followingfeatures may be incorporated. The spacer elements may comprise a largenumber of generally spherical or cylindrical elements. The spacerelements may comprise glass. The glass may be etched and the PIEmaterial may adhere to the etched glass surface. The spacer elements maycomprise plastic. The plastic may be porous and the PIE material mayabsorbed into the porous structure. The spacer elements may comprisehigh-surface area particles that are nanoporous, mesoporous, ormicroporous. The spacer elements may be randomly located in the spacebetween the substrates. The majority of the polymer supports may bebonded to each of the two substrates. The polymer support may generallysurround the exterior of the spacer element. The polymer supports may beprimarily separate members not interconnected with one another. One ormore interconnecting regions of polymer may interconnect a majority ofthe polymer supports. One of the interconnecting regions may comprise alayer of polymer adjacent one of the substrates. The PIE material may beapplied to the spacers before introduction of the spacers to the spacebetween the substrates. The PIE material may be applied to the spacersafter introduction of the PIE elements to the space between thesubstrates. The PIE material may be a coating applied to the spacers.The spacers may be dry sprayed on to the substrate before application ofthe electrooptic material. The spacers may also be wet sprayed on to thesubstrate. A solvent used for wet spraying may comprise a PIE materialor may have a PIE material in solution or suspension. The PIE materialmay comprise one or both of the following: an initiator and anaccelerant of the in situ polymerization process. The PIE material maybe light activated. The PIE material may comprise a photoinitiator. Thephotoinitiator may comprise a plurality of photoinitiators of differentspectral sensitivities, so that polymerization may be initiated atdifferent times in different locations. The light may be ultravioletlight. The PIE material may be heat activated. The PIE material may beself-activated after a period of time following assembly of the display.The PIE material may comprise both a photoinitiator and an accelerant.The electrooptic material and a prepolymer may be applied between thesubstrates as a mixture, and during in situ polymerization a phaseseparation of the electrooptic material and the polymer may occur. Theelectrooptic material may be a liquid crystal material. The electroopticmaterial may be a mesomorphic material. The liquid crystal displaydevice may further include at least one electrode on at least onesubstrate to generate the electric field. The liquid crystal displaydevice may further include at least one electrode on the secondsubstrate. The polymer used for in situ polymerization of the substratesmay comprise an acrylic based adhesive. The polymer used for in situpolymerization of the substrates may comprise an epoxy-based adhesive.The polymer used for in situ polymerization of the substrates maycomprise a urethane-based adhesive. The polymer used may be primarilycured by light. The polymer used may be primarily cured by heat. Thepolymer used may be primarily cured via intermixing of a chemicaladditive.

[0012] The invention provides a display with the low drive voltages ofcurrently-manufactured LC-only displays. It does not generally requirethe use of complex processing steps such as the use of photomasks. Thepolymer structures can, if desired, be self-aligning to features withinthe display. Embodiments can be made using methods that are compatiblewith existing LCD manufacturing methods.

[0013] The invention provides displays that are simple, manufacturable,and that are capable of achieving polymer microstructures that areself-aligned (i.e., no photomask required) and localized to within lessthan about 5 μm. Additional benefits include the adhesion to thesubstrates of the spacing elements used to maintain the proper distancebetween the substrates. This is important since millions of thesemicroscopic spacers may be distributed between the substrates of any ofthe aforementioned display technologies, and the spacers will have atendency to shift upon flexure of the display or when the display issqueezed. Other benefits include the ability to optimize the laminatestructure of the plastic display to provide good performance undercompression as well as peel strength. This last benefit is achieved as aresult of the polymer being localized around and surrounding thespacers; the spacers provide compressive strength while the polymerprovides the peel and shear strength.

[0014] Other features and advantages of the invention will be apparentfrom the following detailed description and from the claims, and fromthe disclosure and claims of my applications entitled, “ElectroopticalDisplays Constructed with Polymerization Initiating and EnhancingElements Positioned Between Substrates,” “Electrooptical Displays withMultilayer Structure Achieved by Varying Rates of Polymerization and/orPhase Separation,” and “Electrooptical Displays Constructed withPolymer-Coated Elements Positioned Between Substrates,” each filed oneven date herewith (and incorporated herein by reference).

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 shows a cross section of a liquid crystal display devicethat uses spherical spacers coated with a photoinitiator prior toexposure to the developing light.

[0016]FIG. 2 shows a cross section of a liquid crystal display devicethat uses spherical spacers coated with a photoinitiator after exposureto the developing light.

[0017]FIG. 3 shows a cross section of a liquid crystal display devicethat uses spherical spacers coated with a accelerator afterpolymerization and exposure to the developing light.

[0018]FIG. 4 shows a cross section of a liquid crystal display devicethat uses a mesh-like spacing membrane.

DETAILED DESCRIPTION OF THE INVENTION

[0019] According to the present invention, in the preferred embodiment,a liquid crystal display device is assembled using the followingprocedure:

[0020] 1. The substrates are a flexible polymer material with a lowlevel of birefringence to improve the optical qualities of the finalproduct and having a glass transition temperature greater than 150degrees C. in order to facilitate the various drying and bakingoperations. A polymer that meets these requirements is poly ethersulphone (PES). A vapor barrier is coated onto the outside surface ofthe substrate to improve the reliability and product life of thedisplay; the vapor barrier is typically composed of a thin film laminatestructure of silicon oxide and another polymer.

[0021] 2. The substrates are coated with a vacuum-deposited layer oftypically indium tin oxide (ITO), which is a transparent conductor. TheITO is then patterned via chemical, electron beam, or laser etching.

[0022] 3. A mixture is prepared of approximately 10% photoinitiatedpre-polymer such as Norland Products NOA-65 and 90% liquid crystal suchas Merck E7. The pre-polymer formulation has been modified such that allphotoinitiator has been removed from the formulation.

[0023] 4. A polyimide solution is coated onto the ITO side of at leastone of the substrates and baked at a temperature of 150 degrees C. forone hour. The polyimide surface(s) are then rubbed to develop analignment layer for the liquid crystal.

[0024] 5. Glass spacers of a diameter of 3-3.5 μm are surface-etchedusing a 1.25% solution of hydrofluoric acid for 10 minutes whilesuspended in solution in an ultrasonic vibration tank. After washing,the etched spacers are then coated with a mixture of methacrylate silaneand a photoinitiator by immersing the spacers into a solution containingthe initiator and an adhesion promoter such as a silane and thenspraying the spacers into the top of a vertical drying column onto thesubstrate(s). Silanes improve the bonding between glass and polymers viachemical bonding at the silane/glass interface and a dispersion of thepolymer into the silane at the silane/polymer interface.

[0025] 6. Spacers are deposited onto the substrate surface in largenumbers (with a density of at least about 30 spacers/mm²). The spacerstend to be distributed generally randomly across the substrate surface.

[0026] 7. The LC/prepolymer mixture is deposited in sufficient quantityonto both inner faces of the substrates, and the substrates arelaminated together while maintaining the proper alignment between theITO patterns on the upper and lower substrates.

[0027] 8. Both sides of the cell are then exposed to UV light thatcauses scission of the photoinitiator and release of free radicalsaround the spacers. The polymerization reaction will then proceed withthe initiation sites centered around each spacer that was deposited withthe initiator.

[0028] 9. The rate of polymerization is set at the beginning of theprocess by adjusting the UV intensity, while the rate of diffusion ofthe LC and pre-polymer is changed by adjusting the reaction temperature.Diffusion rates can also be controlled via the pre-polymer viscosity aswell as by the choice of the LC and pre-polymer to achieve theappropriate degree of miscibility of the two liquids. By adjusting thediffusion and reaction rates, the resulting LC/polymer structure canprovide the desired morphology. For full phase separation, temperaturesshould be in excess of 45 degrees C. with a pre-polymer viscosity lessthan 1000 cps.

[0029] The resulting display is quite flexible. It can be flexed withoutpermanent damage by at least the amount of flexing specified in theflexing tests described in U.S. Pat. No. 6,019,284, hereby incorporatedby reference.

[0030] It is not necessary that polymer form in the vicinity of eachspacer, nor that the polymer extend fully from one substrate to anotherin all cases. Some spacers, for example, may not have been coated withPIE material, or they may have been imperfectly coated.

[0031] Polymer supports that do not extend fully from one substrate tothe other may still be of benefit in creating isolated regions of liquidcrystal, and thereby make possible improved bistability of certainferroelectric liquid crystal materials, which may exhibit improvedbistability if the liquid crystal layer is divided into discretedroplets along one substrate.

[0032] In an alternative embodiment the polymerization initiator is notactivated by light but rather is the ‘accelerator lacquer’ type. Whenusing the an accelerator lacquer initiator, coating of the spacers isaccomplished via the method as previously described, but thepolymerization begins to occur automatically at some time after theLC/polymer mixture is brought into contact with the initiator-coatedspacers. Lamination is performed at room temperature in order tolengthen the time before cure begins. After lamination has beencompleted, the temperature is raised in order to increase thediffusivity of the LC and prepolymer. In addition, the aromatic aminesin the pre-polymer formulation and the peroxide in the lacquer arechosen so as to provide the correct free radical generation rate which,when combined with the diffusion rates of the pre-polymer and LC and thespacings within the display region, result in the polymer localized tothe region surrounding the spacers.

[0033] In another embodiment, the pre-polymer formulation retains itsphotoinitiator component but the spacers are still coated with anadhesion promoter such as a silane coating along with an accelerant oradditional photoinitiator. Typical active ingredients in the accelerantwould be a tertiary amine like dimethyl amino benzene. The curing inthis case will be initiated by both the accelerant and the light. Theaccelerant reaction is allowed to proceed for a sufficient period oftime to localize most of the polymer around the spacers. The lightsource is then turned on on only one side, resulting in a deposition ofany of the remaining polymer along the substrate closest to the lightsource as shown in FIG. 3. This particular embodiment can be furtherrefined by using liquid crystals capable of bistability, i.e., theability to maintain two or more electrooptic states without any electricfield being present. Some examples of such a bistable or multistableliquid crystal are those of the ferroelectric or anti-ferroelectrictype. In a further refinement, the reaction rate is varied during thecourse of polymerization to create a structure in which liquid crystaldroplets interspersed in the polymer are created on the alignmentsurface nearest to the light source and a thin layer of the liquidcrystal is created on the alignment surface opposite the light source asshown in FIG. 4. Both surfaces are aligned in such a configuration so asto produce alignment of the LC molecules on both surfaces, butdroplet-encapsulated LC are known to be a more durable structure interms of maintaining bistability.

[0034] One possible polymer are acrylic adhesives which have excellentoptical clarity as well as the availability of a wide selection ofmanufactured optical grade versions of the material. Other polymers thatmight also be used are, for instance, epoxies or urethanes, thoughtypically these classes of polymers do not have the optical propertiesequal to those of the acrylics. Acrylic adhesives are reactivecross-linking structural adhesives that cure by means of free-radicalinitiation. They are based on the methacrylate monomers and cure byaddition polymerization. The formation of free radicals initiates asudden and rapid chain reaction and curing of the adhesive. Condensationpolymerization, on the other hand, typified by urethane and epoxies,proceeds at an approximately constant, usually lower reaction rate.Generation of free radicals for initiation of polymerization of acrylicbased adhesives can be accomplished by a redox reaction such as thatinvolving dimethyl aniline and peroxide. Because of the nature of thechain reaction, the free radicals can propagate from monomer to monomerand the cure itself can propagate up to 2.5 mm from the point ofpolymerization initiation. As a result of this cure propagationphenomenon, the accelerator and monomer do not have to be fullyintermixed to achieve a full cure. This leads to several other methodsfor curing, where the accelerator can be in the form of a lacquer orthin layer on one surface allowing for the priming and storing of parts.In another related cure method termed ‘honeymoon’ or ‘no-mix’ inindustry parlance, a two part adhesive is used which when brought intocontact with each other (without any intermixing necessary) will resultin the generation of sufficient free radicals to fully polymerize allthe material.

[0035] Acrylics can also be cured by exposure to ultraviolet light lessthan 400 nm in wavelength, and in some instances by light in the visiblerange as well. In the case of photocurable adhesives, the free radicalsource is termed a photoinitiator and results in the formation of feeradicals on exposure to light. Compounds which act as photoinitiatorswith light in the range of 200-300 nm are benzoine ethers, activatedbenzophenones and related compounds; benzyl dialkyl amino morpholinylketone is an example of a visible wavelength-activated photoinitiator.Photoinitiators are disassociated into segments forming free radicals bylight in a process known as scission. One example of an equal mix curingsystem is embodied in U.S. Pat. No. 4,331,795 which uses a cobalt saltaccelerator in one component and a hydroperoxide in the other element.Epoxies may also be formulated that can be UV-cured via cationicpolymerization by incorporating reactive diluents and cyclic monomers.UV-initiated cationic curing of urethanes may be accomplished, forinstance, by basing the formation on vinyl ether and polyurethaneoligomers such as that manufactured by Allied Signal Inc.

[0036] A great variety of embodiments of the invention may be practiced.The PIE material may supply a constituent component of the pre-polymerthat is essential to the initiation of curing but that is left out ofthe LC/pre-polymer mixture. That essential constituent is part of thePIE material and is deposited at one or more of the desired spacingelements within the display region, thus ensuring that initiation andcure will proceed from the desired locations only. The just-mentionedessential constituent component may be a photoinitiator which isactivated when exposed to either UV or visible light via scission. Therate of photopolymerization may be controlled by adjusting the intensityof the light source. The rate of diffusion of the phase separationprocess may be controlled by adjusting the temperature at which thereaction occurs. The rate of the photopolymerization may be variedduring the course of the polymerization process in order to createmultilayer, composite polymer/LC structures. The rate of the phaseseparation may be controlled by adjusting the miscibility of the LC andthe pre-polymer. The rate of the phase separation maybe controlled byadjusting the absolute and relative viscosities of the LC and thepre-polymer. The spacer elements may be coated with an acceleratorlacquer or photoinitiator prior to device assembly and then dry-spraydeposited onto one or more of the substrates. The spacer elements may bedeposited via a wet-spray method in which the solution used as thedeposition vehicle is either strictly composed of an accelerator orphotoinitiator, or includes either or both of these compounds and asolvent, the concentration of which is adjusted to achieve theappropriate quantity of material to fully polymerize the pre-polymerwithin the display region around the spacers. The spacers may be mixedinto a solution of the accelerator or photoinitiator. The solution isthen dispensed in liquid form, via a method such as a pipette, silkscreen or syringe, directly onto macroscopic regions on the substrates.The macroscopic region might be the outside perimeter, therebyautomatically achieving an edge seal of the display duringpolymerization. The spacer elements may be porous structures, and theaccelerator or photoinitiator is then allowed to absorb into the porousmatrix in order to increase the weight percent of accelerator orphotoinitiator in the desired localized region as well as to betterprovide better interpenetration of the polymer and spacing, thusproviding better adhesion. The spacer elements may be composed of glass,typically in the form of beads or rods, which are then etched toincrease the surface area for improved adhesion. One or more layers of aan adhesion promoter such as a silane coupling agent may be coated ontothe glass spacers which may or may not have been etched, prior to thecoating of the glass spacers with the accelerator or photoinitiator. Thespacer elements may be admixed to the photoinitiator or accelerator inconcentrations higher than what would be desired in regions of thedisplay that are active image areas; the mixture is then deposited ontothe substrate via printing or pipette methods into the interpixelregions or the perimeter where no image is presented, thus providedadditional support without adversely affecting the image contrast orquality. The initiator may be solely heat activated or heat activated aswell as photo-activated or other activation method. The polymer ischosen so as to contract following initial bonding to the substrates andupon curing; the two substrates are thus drawn together, increasingdurability of the display; this is particularly effective when thepolymer is localized around the spacer element, as has been previouslydescribed. The spacer element may be one or more sheets of an extensibleporous membrane that when laminated in between the substrates is theelement that determines the spacing between the substrates. In this andother embodiments, one or more of the substrates may be of glass orother rigid material.

[0037] Other embodiments of the invention are within the followingclaims.

What is claimed is:
 1. A liquid crystal display device, comprising: twosubstrates facing and spaced from each other, at least one of thesubstrates being transparent; electrodes positioned to establish anelectric field in the space between the two substrates; one or morespace elements located between the substrates; one or more polymersupports located primarily in the vicinities of the spacer elements, thepolymer supports extending between the two substrates and having beenpolymerized in situ in response to PIE material carried on or within thespacer elements; and electrooptic material filling at least a portion ofthe space between the two substrates.
 2. The liquid crystal displaydevice of claim 1 wherein the spacer elements comprise a large number ofgenerally spherical or cylindrical elements.
 3. The liquid crystaldisplay device of claim 2 wherein the spacer elements comprise glass. 4.The liquid crystal display device of claim 3 wherein the glass is etchedand the PIE material adheres to the etched glass surface.
 5. The liquidcrystal display device of claim 2 wherein the spacer elements compriseplastic.
 6. The liquid crystal display device of claim 5 wherein theplastic is porous and the PIE material is absorbed into the porousstructure.
 7. The liquid crystal display device of claim 2 wherein thespacer elements comprise high-surface area particles that arenanoporous, mesoporous, or microporous.
 8. The liquid crystal displaydevice of claim 2 wherein the spacer elements are randomly located inthe space between the substrates.
 9. The liquid crystal display deviceof claim 1 wherein the majority of the polymer supports are bonded toeach of the two substrates.
 10. The liquid crystal display device ofclaim 1 wherein the polymer support generally surrounds the exterior ofthe spacer element.
 11. The liquid crystal display device of claim 1wherein the polymer supports are primarily separate members notinterconnected with one another.
 12. The liquid crystal display deviceof claim 1 wherein one or more interconnecting regions of polymerinterconnects a majority of the polymer supports.
 13. The liquid crystaldisplay device of claim 12 wherein one of the interconnecting regionscomprises a layer of polymer adjacent one of the substrates.
 14. Theliquid crystal display device of claim 1 wherein the PIE material isapplied to the spacer elements before introduction of the spacerelements to the space between the substrates.
 15. The liquid crystaldisplay device of claim 1 wherein the PIE material is applied to thespacer elements after introduction of the spacer elements to the spacebetween the substrates.
 16. The liquid crystal display device of claim 1wherein the PIE material is a coating applied to the spacer elements.17. The liquid crystal display device of claim 1 wherein the spacerelements are dry sprayed on to the substrate before application of theelectrooptic material.
 18. The liquid crystal display device of claim 1wherein the spacer elements are wet sprayed on to the substrate.
 19. Theliquid crystal display device of claim 18 wherein a solvent used for wetspraying comprises a PIE material or has a PIE material in solution orsuspension.
 20. The liquid crystal display device of claim 1 wherein thePIE material comprises one or both of the following: an initiator and anaccelerant of the in situ polymerization process.
 21. The liquid crystaldisplay device of claim 20 wherein the PIE material is light activated.22. The liquid crystal display device of claim 21 wherein the PIEmaterial comprises a photoinitiator.
 23. The liquid crystal displaydevice of claim 22 wherein the photoinitiator comprises a plurality ofphotoinitiators of different spectral sensitivities, so thatpolymerization may be initiated at different times in differentlocations.
 24. The liquid crystal display device of claim 21 or 22wherein the light is ultraviolet light.
 25. The liquid crystal displaydevice of claim 20 wherein the PIE material is heat activated.
 26. Theliquid crystal display device of claim 20 wherein the PIE material isself-activated after a period of time following assembly of the display.27. The liquid crystal display device of claim 20 wherein the PIEmaterial comprises both a photoinitiator and an accelerant.
 28. Theliquid crystal display device of claim 1 wherein the electroopticmaterial and a prepolymer are applied between the substrates as amixture, and during in situ polymerization a phase separation of theelectrooptic material and the polymer occurs.
 29. The liquid crystaldisplay device of claim 1 or 28 wherein the electrooptic material is aliquid crystal material.
 30. The liquid crystal device of claim 1 or 28wherein the electrooptic material is a mesomorphic material.
 31. Theliquid crystal display of claim 1 further comprising at least oneelectrode on at least one substrate to generate the electric field. 32.The liquid crystal display device of claim 32 further comprising atleast one electrode on the second substrate.
 33. The liquid crystaldisplay device of claim 1 wherein the polymer used for in situpolymerization of the substrates comprises an acrylic based adhesive.34. The liquid crystal display device of claim 1 wherein the polymerused for in situ polymerization of the substrates comprises anepoxy-based adhesive.
 35. The liquid crystal display device of claim 1wherein the polymer used for in situ polymerization of the substratescomprises a urethane-based adhesive.
 36. The liquid crystal displaydevice of claim 1 wherein the polymer used is primarily cured by light.37. The liquid crystal display device of claim 1 wherein the polymerused is primarily cured by heat.
 38. The liquid crystal display deviceof claim 1 wherein the polymer used is primarily cured via intermixingof a chemical additive.
 39. The liquid crystal device of claim 1 whereinthe substrates comprise a flexible polymer material.